Revisiting the Plant Family Collection

By Sarah Schmidt | October 17, 2018

When Brooklyn Botanic Garden was established, more than century ago,
one of its main tenets was to provide not only a respite from the quickly
developing city but also educational resources for plant lovers with all
levels of knowledge, from laypeople to horticulturists to scientists.

To this end, the core collections in the central
part of the Garden were organized by plant
family. This portion of the Garden, also called
the Systematic Section, was designed by
landscape architect Harold Caparn to present
living examples of closely related plants for
side-by-side observation.

Today, this area, now called the
Plant Family Collection, retains its original
organizing principles, but as part of
BBG’s Water Conservation Project, the
area has been reconfigured to enhance
the meandering brook that runs from the
Japanese Hill-and-Pond Garden to the
recently opened Shelby White and Leon Levy
Water Garden. Walking paths have also been
reworked to lead people into the collection
rather than merely alongside it.
“The visitor will follow the brook, passing
over plank bridges and weaving through a
lush garden,” says Jason Siebenmorgen of
Michael Van Valkenburgh Associates (MVVA),
the firm that oversaw the renovation and also
designed the Water Garden. “The familiar
large specimens will be there, but many will be
revealed in a new way as you move through
the landscape. And one dramatic change will be
water flowing through the stream channel and
over rocky falls.”

In his effort to present a living collection
that would show how plants evolved, Caparn
likely drew from collections like the Arnold
Arboretum at Harvard University, which was
established in 1872 and designed by Frederick
Law Olmsted. The arboretum, also arranged
by plant family, was inspired by similar
gardens in Europe. Caparn wrote frequently
in professional journals about the planning
and philosophy behind the Systematic
Section, and in 1915, he described his vision
of a visitor’s experience.

The layman or semi-layman, the gardener,
landscape architect or plant-lover of
any kind, who judges and values plants
according to their outward appearance and
qualities only, will be mildly surprised to
see that alders, witch-hazel, and snowballs,
though they may produce similar mass
effects in planting, are no way akin; while
the elm and the stinging nettle have almost
everything in common except the trifling
difference that one grows a hundred feet
high, weighs a few tons, and lives for 150
years, while the other is a mere weed.
The garden Caparn designed included
about 30 plant families and aligned the
progression of plant evolution from north to
south, beginning with ferns at the periphery of
the Japanese Hill-and-Pond Garden and
continuing south with more evolved plants like
honeysuckles and daisies. —Harold Caparn, 1915

Recent research in plant genetics has brought some changes to
our understanding of the evolutionary history
of higher plants, but the basic scheme still
provides a useful primer in plant evolution.
The current renovation presented an
opportunity to incorporate new plantings
into the historic layout, and MVVA worked
closely with Rowan Blaik, BBG’s director of
Living Collections, to identify new additions.

More than 150 existing trees and shrubs—the
majority of those within the construction
area—were retained in their original places,
while another 27 were transplanted, says Blaik.
Among them is a rare cherry species, Prunus
hirtipes, which was transplanted within the
rose family section. Thousands of new woody
and herbaceous plants will also be added.
In the willow family section, for instance, a
number of low, sprawling species were planted
among several taller willow trees, which
diversified the collection and introduced a
variety of leaf textures, says Siebenmorgen. In
the witch-hazel family, several later-blooming
varieties were planted near a large, mature
Persian ironwood and the witch-hazels and
winter hazels that were already present.

“The ironwood was damaged in a storm
just prior to the work on the Garden but is
recovering now with significant regrowth,” says
Siebenmorgen. “It is surrounded by several
very large and shrubby witch-hazels and winter
hazels, all from the same family. These form
green domes wider than they are tall, almost
like fat clouds sitting on the lawn.”
The newly opened area will also include
along the stream some of the same iris and
sedge species that are in the Water Garden
to help tie the two spaces together. The
design is also meant to draw people closer to
the plants themselves and encourage a more
thoughtful visit.

“Hopefully, visitors will see much more
interplay between the different plant families
and be able to experience the stream in a more
visible way,” says Matt Bird, also of MVVA. “For
those visitors who may be passing through
casually, it will seem to blend easily with the
adjacent spaces, but those who are more
interested in the details of the plant families
will still be able to have that experience.” He
hopes longtime members will see the space
with new eyes: “I’d imagine some are going to
be surprised. I feel like we will be opening an
entirely new space in the Garden.”

Collection Highlights

The taxonomic arrangement of plants that Harold Caparn established
still provides a living primer on plant evolution. A close look at plant
structures can provide family clues.

Ferns

Among the first vascular plants
were the ferns, which appeared
some 300 to 350 million years
ago. Ferns do not bear seeds but
instead form simpler single-celled
reproductive structures, spores,
which can develop into a plantlet
that can fertilize and mature in
moist conditions. This family is
represented by waterside glades
of ferns in the Japanese Hill-and-
Pond Garden.

Conifers

Nearby, wrapping around the
south side of Celebrity Path, are
the conifers—pines, junipers,
cypresses, and their kin—some of
the earliest seed-bearing plants.
Conifers do not produce flowers
or fruit but make pollen and seeds
in woody cones. The seed cone
contains ovules, which, when
fertilized by pollen, become seeds.
The pollen and seeds are dispersed
by wind.

Ginkgo
Ginkgoaceae

Ginkgo biloba is the single
remaining species of a family that
dates back to the Triassic period,
225 to 190 million years ago. It has
fan-shaped leaves and lacks cones.
Its seeds are encased in a fleshy,
malodorous outer coating. Rare
(or extinct) in its native habitat, it
is common in New York City; here
at BBG, specimens can be found in
and near Ginkgo Triangle.

Magnolia Family
Magnoliaceae

Magnolias are among the earliest
flowering plants. They have
many primitive characteristics,
most notably flowers with parts
that are large and not joined
together—numerous petals, sepals,
and stamens arranged in a spiral.
These early flowers generally
lack the bright colors that would
attract insects with more advanced
eyesight.

Elms, Oaks, and Walnuts

A century ago, many botanists
viewed the inconspicuous,
odorless, and often petalless
flowers of the elms (Ulmus), oaks
(Quercus), and walnuts (Juglans)
as a primitive feature. However,
recent scientific research has
shown that these plants have
reverted to wind pollination and
are more highly evolved than once
presumed. They likely appeared
around 60 million years ago.

Heaths and Laurels
Ericaceae

Members of the heath family
show considerable advancement
beyond more primitive flowering
plants like magnolias. As
flowering plants evolved, they
exhibited flowers with fewer
parts. Petals became fused or
partially joined. In the heaths,
petals are fused almost to the
tip, forming a tubular, trumpetshaped
bloom.

Rose Family
Rosaceae

About 50 million years ago, bees
and butterflies became more
diverse and abundant, and flowers
began to evolve with them. Plants
of the rose family developed
structures that protect the female
part of the flower. Rather than
relying on wind pollination, they
depend on insects and other
animals to transfer pollen and
disperse their seeds.

Legume Family
Fabaceae

Closely related to the roses are
the legumes. Many legumes
produce asymmetrical flowers (an
advanced evolutionary feature)
with one large petal above, two
separate lateral petals below,
and two fused lower petals. This
structure evolved specifically for
insect pollination—in fact, some
legumes developed flowers to
attract a single insect species.

Honeysuckle Family
Caprifoliaceae

Honeysuckles, abelias, and
viburnums are all members of this
family. Their distinctive blooms
may be colorful and are often
intensely fragrant. The flowers,
which generally contain sweet
nectar, are tube-shaped and
adapted to the long tongues of
pollinators such as butterflies,
moths, and hummingbirds.

Willow Family
Salicaceae

Plants in the willow family,
which also includes aspens and
cottonwoods, are dioecious,
meaning male and female flowers
appear on separate plants.
Willows typically produce small,
petalless flowers in a structure
called a catkin. They reproduce and
grow quickly, and BBG’s collection
now includes a variety of mature
and new specimens.

Daisy Family
Asteraceae

Among the most advanced of
flowering plants, members of the
daisy family have a distinctive
“composite” flower head, in which
numerous very small flowers are
clustered together. The central
disc consists of many florets, each
made up of five joined petals.
Surrounding the central disk are
ray florets, each with a large,
prominent petal.

Monocot Border

Over 60,000 species, including
grasses and lilies, are grouped as
monocots. They have a singleleaf
seedling, leaves with parallel
veins, and petals and flower parts
in threes or multiples of three.
Simple does not necessarily mean
primitive: Botanists believe that
monocots evolved from dicots
about 100 million years ago by
losing over time one of the two
seed leaves found in every dicot.

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Osmunda claytoniana (interrupted fern) in the Japanese Hill-and-Pond Garden. Photo by Blanca Begert.Ginkgo biloba leaves, in transition to fall color, along the Overlook. Photo by Lee Patrick.Rosa 'Gentle Hermione' in the Cranford Rose Garden. Photo by Jean-Marc Grambert.Honeysuckle (Lonicera heckrottii 'Goldflame') in full bloom near the Herb Garden. Photo by Rebecca Bullene.Dahlia 'Bonne Espérance' (mignon single dahlia) in the Plant Family Collection. Photo by Morrigan McCarthy. Maturing Cedrus deodara cones in the Conifer Collection. Photo by Anne O'Neill.Sweetbay (Magnolia virginiana) is a semievergreen magnolia native to eastern North America. Its creamy-white, fragrant flowers appear in June. Photo by Rebecca Bullene.Kalmia latifolia (mountain laurel) in the Discovery Garden. Photo by Lee Patrick.
Sweet pea (Lathyrus odoratus 'Old Spice Mix') blooms in the Fragrance Garden. Photo by Rebecca Bullene.Rose-gold pussy willow (Salix gracilistyla) shows its bright pollen near the brook at BBG. Photo by Rebecca Bullene.Lilium (lily) 'Anastasia' in the Plant Family Collection monocot border. Photo by Blanca Begert.
The Plant Family Collection reopened in October. Some specimens, like this Japanese elm (Ulmus japonica), planted in 1951, were retained in their original situation. Thousands of new plants were also added. Photo by Sarah Schmidt.Wooden plank bridges and grassy walkways are meant to draw visitors closer to the Plant Family Collection. Photo by Sarah Schmidt.Ulmus glabra 'Camperdownii' (Camperdown elm) in Bluebell Wood. Photo by Blanca Begert.